Process of manufacturing fuel briquettes



Patented Apr. 3, 1928.

UNITED STA res PATENT OFFICE.

ALBERT L. S ILLMAN, 0F PLAINFIELD, NEW JERSEY, ASSIGNOR TO THE GENERAL FUEL IBRIQUETTE CORPORATION, OF NEW YOR YORK.

No Drawing.

This invention relates to the manufacture of briquettes and particularly to fuel briquettes. The principal object of the invention is to provide a new and improved process of manufacturing fuel briquettes by means of which briquettes of high caloric value and of great strength and durability may be produced.

The present invention rests on the discovery that certain types of coal when mixed with a binder consisting of asphalt or pitches which are solid at ordinary temperatures but liquefy at between 110 to 212 F., and the melted liquid with the hot coal are subjected to a severe grinding action, a certain amount of the volatile constitutent of the coal is dissolved in the melted binder, and that such solution hastens the subsequent set of the briquette and increases the tendency of the briquette to resist abrasion and breakage.

It is necessary in order to take advanta e of this discovery to use coal of a certain type, such as will under conditions of severe grinding and the applied heat, give off some volatile material. Goals of this character are, generally speaking, any of the coals known as soft coals, of Which the Pocahontas and New River varieties are particular examples. It is also necessary for the carrying out of the new process that the mixing and grinding action'be of considerable intensity such as results for example from the use of a masticator of the type known in Canadian Patent No'.184,646, of May 28, 1918. Such masticators exercise a kneading effect of considerable severity and consequently facilitate that function of the process which is concerned with the extraction of the volatiles from the hot coal'during the mixing operation. In order to carry out the process advantageously, it is necessary that the coal under treatment be itself heated to a temperature of the order of 125 F. during its mastication, the temperature of the coal to be high enough to maintain the liquidity of the binding ingredients during the operation. It is therefore of advantage to give the masticator during the operation as much heat insulation as possible and it is of still further benefit if the operation be carried on in the presence of water vapor. One salient prac- N. Y., A CORPORATION 01 PROCESS OF MANUI FACTURING FUEL BRIQUETTES.

Application filed January 2}, 1927. Serial No. 162;681.,

tical efi'ect of the process is to decrease markedly the amount of binder required, inasmuch as dissolved coal substance becomes binder substance.

In a particular example of the process, the soft coal, preferably in a comminuted condition, is mixed with asphalt or pitches such as, are solid at ordinary temperatures but-which liquefy at between 100 and 212 F., the asphalt or pitch serving as'the primary binder. The binder material is heated to liquefy it and is then mixed. with the coal in about the proportion of 10% binder to coal. The mixture is subjected to a severe .or intense grinding action in a masticator which is insulated against substantial heat losses, or is otherwise maintained in a heated condition during the grinding operation. By maintaining the mixture at a temperature not lower than 125 F. during the grinding thereof and in any event at least hlgh enough to maintain the binder in a liquid state, a certain amount of the volatile constituents of the coal is liberated and is dissolved in the melted binder forming secondary binder substances. After being thus treated, the material is briquetted.

It is ofconsiderable importance during the grinding operation, to prevent the temperature of the mixture from falling below a degree at which there would be no Vola-' tilization of" the constitutents of the coal,

and therefore it is of advantage to give the grinding operation as much heat insulation as possible. The provision of such insulation is preferred because while a similar result could obviously be obtained by the external application of heat to the grinder,

such external application would necessarily quettes, the improvement which consists in mixing bituminous coal with a bituminous binder heated to a molten condition, and subjecting the mixture at a temperature above the fusion point of the binder and in the presence of water vapor to an intense grinding operation until volatile constituents of the coal are liberated and passed into solution in the molten binder.

2. In the process of making fuel briquettes, the improvement which consists in mixing bituminous coal with a bituminous binder heated to a molten condition, and subjecting the mixture at a temperature above 125 F. and in the presence of steam to an intense grinding operation until volatile constitutents of the coal are liberated and passed into solution in the molten binder. I

In testimony whereof I have hereunto 20 set my hand.

ALBERT L. I STILLMAN. 

